Method of finishing paper boxes



Sept 29, 1936.

c. CLAFF 2,0 6,09

METHOD OF FINISHING PAPER BOXES Filed NOV.

,n mmi L V P43 5 "z 1 Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE 2,056,092 i METHOD or rmisnmo PAPER noxns Clarence Lloyd Clafl, Randolph, Mass.

-Applicatlon November 22, 1935, Serial No. 51,160

1 Claim. (Cl. 93-36) This invention relates to a new and improved method of producing stiff paper boxes and/or box lids out of box board material.

Many boxes of this type are made by providing end wings on the side walls which are extended toward each other and then lapped or straddled by an end fold. Where the box has been made of heavy stock thick rough edges have been exposed at the outer sides of the end folds and these have been objectionable because unsightly. Various expedients have been resorted to in an effort to eliminate the exposure of these rough edges but they have all required special handling and skill which have added to the cost of produc- 5 tion and thus been discarded for economical reasons.

An object of the present invention is to effect the desired results by so cutting through both the boxboard material and its covering or fin- 20 ishing material, that when the folds are assembled and subjected to pressure, the rough edges will be substantially obliterated and a neat, smooth surface presented by the ends of the formed box.

5 Another object is to utilize a method whereby the boxboard material and the outer covering of finishing paper of the like can be assembled into a single web prior to the cutting operation and each cut made through all thicknesses of the 30 web thus produced, so that no special skill is required, such as the separate shaping of the respective thicknesses of the material and their subsequent assembly to form a blank, or the shaping of the edges of one of the assembled 35 thicknesses without injury to the covering material afiixed thereto.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in certain steps in the 40 method of producing a box or box lid, which will be hereinafter described and pointed out in theclaim, it being understood that changes may be made in the method disclosed without departing from the spirit of the invention asclaimed. 45 In the accompanying drawing the several steps of the method have been illustrated.

In said drawing Figure 1 is a plan view of one end of a blank formed from webs of boxboard and finishing or covering paper or the like, said end having been set up into box form.

Figure 2 is a section on line 2-4, Figure 1 showing cutting elements adjacent thereto and 55 the bias cuts produced thereby.

Figure 3 is a perspective view of one end portion 01 the formed box or lid.

Figure 4 is a horizontal section through one corner portion of the box or lid showing the relative positions of the parts after the folding but 5 prior to the pressing operation.

Figure 5 is a similar view on line 55, Figure 3, showing the positions of the parts after the formation of the box has been completed.

In carrying out the method constituting this 10 invention one or more layers of boxboard I are assembled with a layer of covering or finishing paper 2 or the like, the layers being glued together and the sides 3 of the finishing material being turned over and affixed to the side edges of the layer I.

Following the assembly of the layers to form a web, the said web is scored or creased longitudinally as at 4 to separate the sides 5 from the bottom portion 6 of a blank and is then scored or creased transversely as at 1 to form an end fold 8 having an intermediate score or crease extending from side to side as at 9.

The blank is-then cut across the end fold 8 in line with the scores 4 and up to the score I so as to form slots I 0 which separate the end fold 8 from side wings H. During or subsequent to the slotting operation the sides of the fold are subjected to the action of cutters l2 which converge away from the uncoated or inner side of the blank so that said edges will be cut on a bias for a desired distance, as indicated at l3, each side coming to a feather edge M where it is out through the covering material 2. As shown in Figure 1 the bias cuts can be located between the scores or creases l and 9 but it is to be understood tliat, if desired, they can be extended the entire length of the side edges of the end fold.

The bias cuts are at such angles that the surfaces of the edges l3 of each end fold 8 will diverge toward the material 2.

' After the blank has been shaped and then severed from its web it is shaped up by bending the sides 5 into positions perpendicular to the bottom I, and by turning the opposed wings I l into alinement. The end fold v8 is then bent over these wings so as to straddle them and at the same time they are afl'lxed thereto. During or after the bending of the end fold its bias cut edges 13 are subjected to heavy pressure .from a suitable die so that said edges will be pressed from the positions shown in Figure 4 back against the wings I l as shown in Figure 5, thus bringing the feather edges l4 against the wings and causing the covering material 2 to completely conceal the raw side edges of the boxboard material I. Consequently the resultant box will be neat and smooth and will not have the objectionable thick exposed edges usually presented.

What is claimed is:

The method of producing a paper box which includes the steps of assembling layers of boxboard and covering material to form a web, shaping from the web a blank having a bottom, sides, side wings and end folds, cutting the end folds to produce side edges on a bias diverging toward feather edges formed at the outer surface of the covering material, thereafter folding the blank with the end folds astride and affixed to the side wings, and finally subjecting the end folds to compression to flatten out the bias edges against CLARENCE LLOYD CLAFF. 

